<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./css/inputnumber.css" />
    <link rel="stylesheet" href="./css/index.css" />
    <title>购物车</title>
  </head>
  <body>
    <div class="app-container" id="app">
      <!-- 顶部banner -->
      <div class="banner-box"><img src="img/fruit.jpg" alt="" /></div>
      <!-- 面包屑 -->
      <div class="breadcrumb">
        <span>🏠</span>
        /
        <span>购物车</span>
      </div>
      <!-- 购物车主体 -->
      <div class="main" v-if="fruitList.length>0">
        <div class="table">
          <!-- 头部 -->
          <div class="thead">
            <div class="tr">
              <div class="th">选中</div>
              <div class="th th-pic">图片</div>
              <div class="th">单价</div>
              <div class="th num-th">个数</div>
              <div class="th">小计</div>
              <div class="th">操作</div>
            </div>
          </div>
          <!-- 身体 -->
          <div class="tbody">
            <div v-for="(item,index) in fruitList" :key="item.id" class="tr" :class="{active : item.isChecked}">
              <div class="td"><input type="checkbox" v-model="item.isChecked" /></div>
              <div class="td"><img :src="item.icon" alt="" /></div>
              <div class="td">{{item.price}}</div>
              <div class="td">
                <div class="my-input-number">
                  <button class="decrease" :disabled="item.num===1 " @click="sub(item.id)"> - </button>
                  <span class="my-input__inner">{{item.num}}</span>
                  <button class="increase" @click="add(item.id)"> + </button>
                </div>
              </div>
              <div class="td">{{item.num+item.price}}</div>
              <div class="td"><button @click="del(item.id)">删除</button></div>
            </div>
          </div>
        </div>
        <!-- 底部 -->
        <div class="bottom">
          <!-- 全选 -->
          <label class="check-all">
            <input type="checkbox" v-model="isAll" />
            全选
          </label>
          <div class="right-box">
            <!-- 所有商品总价 -->
            <span class="price-box">总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{totalPrice}}</span></span>
            <!-- 结算按钮 -->
            <button class="pay">结算({{ totalCount }})</button>
          </div>
        </div>
      </div>
      <!-- 空车 -->
      <div class="empty">🛒空空如也</div>
    </div>
    <script src="../../js/vue.js"></script>
    <script>
      const defaultArr = [
                {
                  id: 1,
                  icon: "LearningVue/第二天/13-综合案例-购物车/img/huolongguo.png",
                  isChecked: true,
                  num: 2,
                  price: 6,
                },
                {
                  id: 2,
                  icon: "LearningVue/第二天/13-综合案例-购物车/img/荔枝.png",
                  isChecked: false,
                  num: 7,
                  price: 20,
                },
                {
                  id: 3,
                  icon: 'LearningVue/第二天/13-综合案例-购物车/img/榴莲.png',
                  isChecked: false,
                  num: 3,
                  price: 40,
                },
                {
                  id: 4,
                  icon: 'LearningVue/第二天/13-综合案例-购物车/img/鸭梨.png',
                  isChecked: true,
                  num: 10,
                  price: 3,
                },
                {
                  id: 5,
                  icon: 'LearningVue/第二天/13-综合案例-购物车/img/樱桃.png',
                  isChecked: false,
                  num: 20,
                  price: 34,
                },
      ]
      const app = new Vue({
        el: '#app',
        data: {
          // 水果列表
          fruitList:JSON.parse(localStorage.getItem('list')) || defaultArr,
        },
        computed:{
          isAll: {
            get() {
              //every()检查数组所有元素是否都满足条件，返回布尔值（全满足为 true ，否则 false ）
              return this.fruitList.every(item => item.isChecked)
            },
            set(value) {
              // 基于拿到的布尔值，要让所有的小选框 同步状态
              this.fruitList.forEach(item => item.isChecked = value)
            }
          },
          totalCount(){
            // return this.fruitList.reduce((sum,item)=>{
            //   if(item.isChecked){
            //     //选中->需要累加
            //     return sum+item.num
            //   }else{
            //     return sum
            //   }
            // },0)
            let sum = 0;
            this.fruitList
                    .filter(item => item.isChecked) // 筛选出isChecked为true的项
                    .forEach(item => {
                      sum += item.num; // 累加num值
                    });
            return sum

          },
          totalPrice(){
            return this.fruitList.reduce((sum,item)=>{
              if(item.isChecked){
                return sum+item.num*item.price
              }else{
                return sum
              }
            },0)
          }
        },
        methods: {
          add(id) {
            //找到数组中id对应项
            const fruits = this.fruitList.find(item => item.id === id)
            fruits.num++
          },
          sub(id) {
            //找到数组中id对应项
            const fruits = this.fruitList.find(item => item.id === id)
            fruits.num--
          },
          del(id) {
            this.fruitList = this.fruitList.filter(item => item.id !== id)
          }
        },
        watch:{
          fruitList:{
            deep:true,
            handler(newValue){
              //需要将变化后的newValue存在本地（转json）
              localStorage.setItem('list', JSON.stringify(newValue))
            }
          }
        }
      })
</script>
  </body>
</html>
